Abstract Traumatic brain injury (TBI) is major source of disability and death for older adults. Of particular concern is that older adults most frequentl sustain TBIs after low-mechanism injuries, such as falls from standing height, and frequently use anticoagulants and platelet inhibitors, which place them at risk for worse clinical outcomes. With the growth of the older adult population and the expanding use of anticoagulants and platelet inhibitors, TBI among older adults will continue to be a major source of morbidity and mortality unless methods are identified to improve outcomes in this unique population. Our overall goal in this proposed study is to describe the current prehospital trauma triage process for older adult (agee55) patients with suspected TBI, to identify the effect of anticoagulants and platelet inhibitors on TBI-related need for trauma center services, and to identify novel TBI screening strategies that are feasible for use in the prehospital setting. We will build upon our long-standing and highly successful EMS research laboratory that has specifically focused on the triage of injured patients and the prehospital care of older patients. We will employ a combination of qualitative and quantitative methods, collecting data from a large, multi-county catchment area that includes multiple EMS agencies, urban and rural environments, as well as trauma centers and non-trauma centers. In this study, we will: 1) identify candidate neurologic scales to maximize detection of high-risk older adult TBI patients; 2) characterize the current trauma triage process used by EMS providers to identify older patients with suspected TBI and patients taking anticoagulants and/or platelet inhibitors; 3) assess the public health burden of TBI among older adult EMS patients taking anticoagulants and/or platelet inhibitors; 4) assess the predictive ability of novel prehospital-based neurologic screening strategies to identify high-risk older adult TBI patients in the prehospital setting who require TBI- related trauma center care. Findings from this study have the potential to shift clinical practice in the prehospital setting by informing future recommendations for the identification of TBI among older adults taking anticoagulants or platelet inhibitors.